(GPS use of calibrating precise time for PC/Network)Tardis is a shareware utility for Windows that makes sure your PC clock tells the right time. It can find out what the right time is in various ways including accessing internet-based Atomic Clocks, using networked timeservers, GPS (The Global Positioning System), and by listening for time broadcasts over an LAN. http://www.kaska.demon.co.uk/

VisualGPS (NMEA viewer & data logger/playback)

VisualGPS is a general purpose utility for monitoring the output from a GPS receiver. VisualGPS uses the serial protocol from the National Marine Electronics Association (NMEA) version 2.20. VisualGPS is setup as purely a listener and will show information interpreting the following sentences:

GPGGA - Global Positioning System Fix Data

GPGSA - GNSS DOP and Active Satellites

GPGSV - GNSS Satellites in View

SA Watch (GPS receiver analyzer)

SA Watch allows you to monitor and analyze the wandering that your GPS receiver appears to do when it is at a fixed location. Originally, this wandering was largely the result of SA - Selective Availability - DOD - speak for the deliberate degradation of the accuracy of your GPS signal. When SA was eliminated as a source of position error, we got our first good look at the remaining errors. SA Watch lets you see these graphically and statistically.http://huntting.com/sawatch/index.html

GPSS

(Moving Map Software)

GPSS Software from Sunninghill in UK for In-car navigation & Remote Tracking with USA & World maps.
GPS software is available at Sunninghill Systems: http://www.gpss.co.uk This includes free mapping for 155 countries: down to street level for all USA.